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Step 2: Assign the Age of Water Flag to the Dye Decay Rate
Using a value of 1000 for the Dye Decay Rate activates a flag in EFDCPlus so that EFDC_Explorer will treat Selecting the Age radial button option effectively treats the dye constituent as an age counter. Every timestep the dye constituent is transported in a method similar to all other water column constituents. At the end of the dye transport the water is "aged" by adding the delta-T in days, to the dye constituent. The result is the dye constituent represents the age of water in days.
Step 3: Zero Dye Boundary Conditions
The standard approach is to assume that all incoming water to the model domain has an age of zero days, i.e. "new" water. To do this the user should set all boundary condition dye concentrations and/or series to 0. The following is an example of the flow boundary type. The same approach would be used for pressure or withdrawal/return.
Step 4: Save the Project
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